Vegetables are the main source of nitrate food contamination. More than 80% of nitrates are consumed by humans through vegetables. The present study was conducted to investigate the contamination of nitrite and nitrate vegetables in Iran. In this systematic overview we reviewed all internal and external databases for relevant articles. According to different studies, contamination was detected in different types of vegetables in different regions of Iran. Articles that examined nitrite values above the standard limit were not reported. Due to nitrate contamination in vegetables in some cities of Iran and the effects of this nitrogen combination on human health, it is necessary to find a solution in this regard.